Flowmeter



S. M. UDALE FLOWMETER Jan., 16', 1945.

Filed NOV. 22, 1943 Patented.v 1li, 1 I

UNIT-'tio STATES .-'PATENT loFFl-cr.

FLowME'rEn stanley'M. Udale, Detroit, Mich.. ass'ignor to George M.Holley and Earl Holley v Apnlicatmnmvember 2z, i943, sei-1am. 511,376

' f 1 Claim.- l'cl. 'J3- 207) The object of this invention is toenable avflowmeter which is adapted to'read.relatively large fuel ows to also.read fuel OWs-of relatively small value and to read these swith greateraccuracy than the larger flows.

With an ordinary owmeter, the readings become progressively greater asthe flow increases. The result is that when making the readings formaximum flows the gauge is more accurate than when reading at low ows,but obviously, f-uel economy is of more interest at low fuel ows than itis at. maximum ows.

The result is that the ordinary ilowmeter gives accurate readings forhigh :fuel flows and gives relatively inaccurate readings at low owswhen an accurate reading is of greater importance. I have discoveredthat if a needle is inserted in the venturi which is made larger thandesirable for the minimum flows, the readings Q The lower end of .thelever P indicates on a dial R the quantity of fuel flowing through theventuri C.

Any leakage of fuel along the shaft O fwill not iniluence the accuracyof the readings appreciably.

Operation In the operation of the device, nfuel enters at A and owsthrough the passage B, passing lo through the vapor separator Wlocatedbetween the entrance A and the lpassage B. T hevfuel next ilows to theventuri C in which slides the needle D. A depression set up in thethroat ofthe venturi C is transmitted to the chamber V located above thechamber F and the chamber F communicates with the pressure of the fuelat the entrance of the venturi C through the passage G. The opening H inthe rod D in the passage B communicates the pressure in the pasat lowows are made as accurately as possible. 20 sage B to the chamber J whichis Separated from and then when a critical flow is exceeded, if theventuril is automatically made larger by With- .drawing the needle, thenrelatively large flows -can be readv without excessively large movementof the indicating means,

The drawing shows diagrammatically the elements of my invention. Thefuel ofws into the vapor separator W provided with the usual float^andvneed1e valve Z for the escape of vazpor. The fuel then ows througha restricted annular passage B and then flows through the variableventuri C. In the center of both passage B and venturi C is a rod D.That portion of the rod D located in the passage B is cylindrical, the

tapered portion of therod D being in the throat-35 -ci the venturi C.The pressure diil'erence created in. the annular passage B istransmitted' through the orifice H to a chamber J below a diaphragm K.'Ihe diaphragm K is thus drawn down compressing the spring N. The needleD is guided by' means of the element L which also acts as a stop in'both directions. The projection` M on the end of the needle D beingguided in the element L limits the upward movement of the diaphragm Kand also limits the depression of the diaphragmK.; Pressure differencescreated in the venturi C are transmitted through the passage U to thechamber V and through the passage G to the chamber F. The diaphragm Ewhich separates the chambers V and F isconnected to a rod O. In orderthat there should be no packing around the shaft O, similar balanceddiaphragms S and Y are provided. 'I'he chair? ber X to the left of thediaphragm R is ccinected through a passage to the chamber F. A stop Tlimits the movement of the rod O to the right. 'I'he rod O, as it movesto the left,

engages with a lever P which compresses a spring the fuel entrance A bythe diaphragm K. A stop L and a guided projection M determine the travelof the diaphragm K in both directions. The dia'- phragm K is supported'by the spring N so the diaphragm K responds to the influence of theflow' through the passage B and initially the diaphragm K and the needleD are lin 'a position which restricts the throat of the venturi C sothat the venturi C gives a reading at relatively low fuel flows. Thesereadings are determined by the diu'erence of pressure in the twochambers V and F and by the strength of the spring Q.

In the position shown, which corresponds to the position for relativelyhigh fuel ows, the area of the venturi C is almost at its maximum; henceth eieqt of the fuel ow through the venturi C is at a minimum. Thus thereadings for the maximum iiow are not excessively great 4o as they wouldbe if a flxedyenturi was used.

The ideal arrangement is that all the scale divisions on the scale Rhave an equal value in pounds per hour. but this is not necessary. iUntil a minimum fuel ow is exceeded, the

needle D remains in its upper position from which it is not moved untilthe' fuel ilow exceedsa predetermined minimum ilow.

What I claim is:

In a ilowmeter. a. restricted fuel passage oi constant area. a meteringventuri connected thereto, a tapered needle located in the throat ofsaidgmetering venturi, .means `responsive to the drop of pressure in thefuel passage for moving the needle in said metering venturi, meansresponsive to the pressure drop in the throat of the metering venturiVfor indicating fuel flow.

4"""isijllmznsiv M. UDALE.

